ABSTRACT
Primary hyperaldosteronism is the most frequent cause of secondary hypertension. However, it can also be found in apparently normotensive patients, often associated with recurrent hypokalemia and isolated hypertensive episodes. We hereby present the case of a normotensive 50-year-old female patient with a surgical left kidney mass; however, after anaesthetic induction, surgery was aborted due to a severe hypertensive crisis. She was referred to our Hypertension Outpatient Clinic to rule out pheochromocytoma/ paraganglioma. The anamnesis revealed unexplained episodes of hypokalemia. Ambulatory blood pressure monitoring showed normal mean values of blood pressure and heart rate, with an isolated hypertensive peak. Plasma glucose, ions, creatinine, lipids, metanephrines and chromogranin A were normal, but plasma aldosterone was clearly elevated with suppressed plasma renin activity and high aldosterone/renin activity ratio. Primary aldosteronism was confirmed by the captopril test. Abdominal CT was compatible with left adrenal hyperplasia. Treatment with low-dose spironolactone was well tolerated and resulted in normal blood pressure, normokalemia and unsuppressed plasma renin activity. The patient underwent successful laparoscopic removal of a renal oncocytoma. We conclude that normotensive primary aldosteronism is not harmless; it can be associated with severe hypokalemia, anxiety, depression, hypertensive crisis and cardiovascular damage. Patients can also develop resistant hypertension. Adequate treatment can decisively improve the survival and quality of life of the patients with primary aldosteronism, but a correct diagnosis is needed first. Therefore, it must be considered as a diagnostic possibility in normotensive patients with unexplained hypokalemia or isolated hypertensive episodes.